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#include <cstdio>

using namespace std;

int main() {
    int n;
    scanf("%d", &n);

    int ones = 0;
    while (n--) {
        int a;
        scanf("%d", &a);
        if (a == 1) ones++;
        if (ones == 2) break;
    }

    printf("%d\n2\n1 2\n", 2 - ones);

    return 0;
}